Hydrangea plant named ‘SMHMTAU’

ABSTRACT

A new and distinct cultivar of  Hydrangea  plant named ‘SMHMTAU’, characterized by its compact, upright, outwardly spreading and mounded plant habit; strong and sturdy stems; remontant flowering habit; thick dark green-colored leaves; mophead-type inflorescences that can easily be “blued” with aluminum sulfate treatments; and good garden performance.

Botanical designation: Hydrangea macrophylla.

Cultivar denomination: ‘SMHMTAU’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct Hydrangea plant,botanically known as Hydrangea macrophylla and hereinafter referred toby the name ‘SMHMTAU’.

The new Hydrangea plant is a product of a planned breeding programconducted by the Inventor in Grand Haven, Mich. The objective of thebreeding program was to develop new reblooming Hydrangea plants withstrong stems and attractive inflorescences.

The new Hydrangea plant originated from a cross-pollination conducted bythe Inventor in June, 2008 of Hydrangea macrophylla ‘Robert’, disclosedin U.S. Plant Pat. No. 20,020, as the female, or seed parent andHydrangea macrophylla ‘ES1’, not patented, as the male, or pollen,parent. The new Hydrangea plant was discovered and selected by theInventor as a single flowering plant from within the progeny of thestated cross-pollination in a controlled environment in Grand Haven,Mich. in July, 2010.

Asexual reproduction of the new Hydrangea plant by softwood cuttings ina controlled environment in Grand Haven, Mich. since July, 2010 hasshown that the unique features of this new Hydrangea plant are stableand reproduced true to type in successive generations of asexualreproduction.

SUMMARY OF THE INVENTION

Plants of the new Hydrangea have not been observed under all possiblecombinations of environmental conditions and cultural practices. Thephenotype may vary somewhat with variations in environmental conditionssuch as temperature and light intensity without, however, any variancein genotype.

The following traits have been repeatedly observed and are determined tobe the unique characteristics of ‘SMHMTAU’. These characteristics incombination distinguish ‘SMHMTAU’ as a new and distinct Hydrangea plant:

-   -   1. Compact, upright, outwardly spreading and mounded plant        habit.    -   2. Strong and sturdy stems.    -   3. Remontant flowering habit.    -   4. Thick dark green-colored leaves.    -   5. Mophead-type inflorescences that can easily be “blued” with        aluminum sulfate treatments.    -   6. Good garden performance.

Plants of the new Hydrangea differ from plants of the female parent,‘Robert’, in the following characteristics:

-   -   1. Plants of the new Hydrangea are more compact than plants of        ‘Robert’.    -   2. Sterile flower sepals of plants of the new Hydrangea are        richer and more intense in color than sterile flower sepals of        plants of ‘Robert’.

Plants of the new Hydrangea differ from plants of the male parent,‘ES1’, in the following characteristics:

-   -   1. Plants of the new Hydrangea have thicker leaves than plants        of ‘ES1’.    -   2. Sterile flower sepals of plants of the new Hydrangea are        richer and more intense in color than sterile flower sepals of        plants of ‘ES1’.

Plants of the new Hydrangea can be compared to plants of Hydrangeamacrophylla ‘Berner’, disclosed in U.S. Plant Pat. No. 22,329. Inside-by-side comparisons, plants of the new Hydrangea differed primarilyfrom plants of ‘Berner’ in the following characteristics:

-   -   1. Sterile flower sepals of plants of the new Hydrangea were        richer and more intense in color than sterile flower sepals of        plants of ‘Berner’.    -   2. Sterile flower sepals of plants of the new Hydrangea had        entire margins whereas sterile flower sepals of plants of        ‘Berner’ had serrate margins.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the unique appearance ofthe new Hydrangea plant showing the colors as true as it is reasonablypossible to obtain in colored reproductions of this type. Colors in thephotographs may differ from the color values cited in the detailedbotanical description which accurately describe the colors of the newHydrangea plant.

The photograph on the first sheet comprises a top perspective view of atypical plant of ‘SMHMTAU’ grown in an outdoor nursery.

The photograph on the second sheet is a close-up view of a typicalinflorescence of ‘SMHMTAU’.

DETAILED BOTANICAL DESCRIPTION

Plants used for the aforementioned photographs and the followingdescription were grown during the summer in three-gallon containers andin ground beds in an outdoor nursery in Grand Haven, Mich. and undercultural practices typical of commercial Hydrangea production. Plants ofthe new Hydrangea were three years old when the photographs anddescription were taken. Some plants were treated with aluminum sulfateto “blue” the flowers. In the following description, color referencesare made to The Royal Horticultural Society Colour Chart, 1995 Edition,except where general terms of ordinary dictionary significance are used.

-   Botanical description: Hydrangea macrophylla ‘SMHMTAU’.-   Parentage:    -   -   Female, or seed, parent.—Hydrangea macrophylla ‘Robert’,            disclosed in U.S. Plant Pat. No. 20,020.        -   Male, or pollen, parent.—Hydrangea macrophylla ‘ES1’, not            patented.-   Propagation:    -   -   Type cutting.—By softwood cuttings.        -   Time to initiate roots, summer.—About 18 days at            temperatures about 27° C.        -   Time to produce a rooted young plant, summer.—About 60 days            at temperatures about 27° C.        -   Root description.—Fine to thick; white and brown in color.        -   Rooting habit.—Freely branching; dense.-   Plant description:    -   -   Plant form and growth habit.—Perennial deciduous shrub;            compact, upright, outwardly spreading and mounded plant            habit; inverted triangle; strong and sturdy lateral            branches; freely branching habit with about 24 lateral            branches developing per plant; vigorous growth habit.        -   Plant height.—About 81 cm.        -   Plant diameter or area of spread.—About 36 cm.        -   Lateral branches.—Length: About 38 cm. Diameter: About 4 mm.            Internode length: About 6.5 cm. Texture: Smooth, glabrous.            Strength: Strong, sturdy. Aspect: Erect to about 20° from            vertical. Color: Close to 145B.-   Leaf description:    -   -   Arrangement.—Opposite, simple.        -   Length.—About 15.5 cm.        -   Width.—About 10.5 cm.        -   Shape.—Elliptic.        -   Apex.—Acuminate.        -   Base.—Obtuse.        -   Margin.—Serrate.        -   Texture, upper and lower surfaces.—Smooth, glabrous;            leathery and thick.        -   Venation pattern.—Pinnate.        -   Color.—Developing leaves, upper surface: Close to 143A.            Developing leaves, lower surface: Close to 146B. Fully            expanded leaves, upper surface: Close to 137A; venation,            close to 145C. Fully expanded leaves, lower surface: Close            to 146B; venation, close to 145C.        -   Petioles.—Length: About 2 cm. Diameter: About 4 mm. Texture,            upper and lower surfaces: Smooth, glabrous. Color, upper and            lower surfaces: Close to 145B.-   Flower description:    -   -   Flower type and habit.—Single sterile and fertile flowers            arranged on terminal mophead cymes that are roughly            hemispherical in shape; flowers face upright to outwardly.        -   Fragrance.—None detected.        -   Natural flowering season.—Plants flower throughout the            summer in Grand Haven, Mich.; flowering remontant; flowers            persistent.        -   Quantity of flowers.—Freely flowering habit; about 50            fertile flowers and about 210 sterile flowers developing per            inflorescence.        -   Inflorescence height.—About 8.5 cm.        -   Inflorescence diameter.—About 14 cm.        -   Flower diameter, fertile flowers.—About 1 cm.        -   Flower depth (height), fertile flowers.—About 5 mm.        -   Flower diameter, sterile flowers.—About 3.3 cm.        -   Flower depth (height), sterile flowers.—About 4 mm.        -   Flower buds, fertile and sterile flowers.—Length: About            5 mm. Diameter: About 3 mm. Shape: Obovate. Color: Close to            1D.        -   Petals, fertile flowers only.—Quantity and arrangement:            About five in a single whorl. Length: About 4 mm. Width:            About 2 mm. Shape: Ovate. Apex: Acute. Base: Cuneate.            Margin: Entire. Texture, upper and lower surfaces: Smooth,            glabrous. Color: When opening, upper and lower surfaces:            Close to 2D. Fully opened, upper and lower surfaces: Close            to 2D.        -   Sepals, fertile flowers.—Quantity and arrangement: If            present, four or five in a single whorl. Length: About            1.5 cm. Width: About 2 cm. Shape: Ovate. Apex: Acute. Base:            Obtuse. Margin: Entire. Texture, upper and lower surfaces:            Smooth, glabrous. Color, not treated with aluminum sulfate:            When opening and fully opened, upper surface: Close to            between 62A and 68B. When opening and fully opened, lower            surface: Close to between 62A and 68B. Color, treated with            aluminum sulfate: When opening and fully opened, upper            surface: Close to 95D. When opening and fully opened, lower            surface: Close to 95D.        -   Sepals, sterile flowers.—Quantity and arrangement: About            four to five in a single whorl. Length: About 1.5 cm. Width:            About 2 cm. Shape: Ovate. Apex: Acute. Base: Obtuse. Margin:            Entire. Texture, upper and lower surfaces: Smooth, glabrous.            Color, not treated with aluminum sulfate: When opening and            fully opened, upper surface: Close to between 62A and 68B.            When opening and fully opened, lower surface: Close to 62A.            Color, treated with aluminum sulfate: When opening and fully            opened, upper surface: Close to 93C and 100B. When opening            and fully opened, lower surface: Close to 94B.        -   Pedicels, fertile flowers.—Angle: About 40° to 50° from            inflorescence axis. Strength: Strong, sturdy. Length: About            5 mm. Diameter: About 1 mm. Texture: Pubescent. Color,            developing: Close to 4D. Color, developed and not treated            with aluminum sulfate: Close to 62A. Color, developed and            treated with aluminum sulfate: Close to 96B.        -   Pedicels, sterile flowers.—Angle: About 50° to 60° from            inflorescence axis. Strength: Strong, sturdy. Length: About            2.5 cm. Diameter: About 2 mm. Texture: Pubescent. Color,            developing: Close to 4D. Color, developed and not treated            with aluminum sulfate: Close to 62A. Color, developed and            treated with aluminum sulfate: Close to 96B.        -   Reproductive organs, observed on fertile flowers            only.—Stamens: Quantity per flower: About ten. Anther shape:            Round. Anther length: About 1 mm. Anther color: Close to 4D.            Pollen amount: Scarce. Pollen color: Close to 4D. Pistils:            Pistil quantity per flower: About three. Pistil length:            About 6 mm. Stigma shape: Round. Stigma color: Close to 95A.            Style length: About 4 mm. Style color: Close to 99B. Ovary            color: Close to 96B.        -   Seeds, observed on fertile flowers only.—Quantity per            inflorescence: Numerous. Size: Less than 0.1 mm by less than            0.1 mm; dust-like. Color: Brown.-   Disease & pest resistance: Plants of the new Hydrangea have not been    observed to be resistant to pathogens and pests common to Hydrangea    plants.-   Garden performance: Plants of the new Hydrangea have been shown to    exhibit good garden performance and to resist sun-scalding. Plants    of the new Hydrangea have been observed to tolerate temperatures    ranging from about −30° C. to about 36° C.

It is claimed:
 1. A new and distinct Hydrangea plant named ‘SMHMTAU’ asillustrated and described.